The present invention relates to apparatus and/or method for controlling a distribution of driving force of a vehicle having an engine, a first motor, and a second motor.
Japanese Patent Application Publication No. 2004-222413 (patent document D1) discloses a hybrid four-wheel-drive vehicle equipped with an engine, a first motor mechanically coupled with the engine and front wheels and electrically coupled with a battery, and a second motor mechanically coupled with rear wheels and electrically coupled with the battery.
Moreover, Japanese Patent Application Publication No. 2004-189067 (patent document D2) discloses a (non-hybrid) four-wheel-drive vehicle in which front-to-rear distribution ratio and left-to-right distribution ratio of rear wheels are controlled in order to achieve a neutral steer. In this technique, the front-to-rear distribution ratio is continuously varied in the range between 30:70 and 70:30, and the left-to-right distribution ratio of rear wheels is continuously varied in the range between 100:0 and 0:100.